Development of software can be challenging. During the development of software, computer program code can be written by one or more developers. Often, complex software includes code written by teams of developers. Accordingly, different portions of the code can be written by different developers. In addition, the code can be written at different times, during different phases of the software development cycle. For example, original code may be reviewed and tested to identify defects in the code. Defects may be addressed by modifying the original code. New defects can sometimes be added to the software by the modifications.